rmorris

Oil won't help if there's excessive track wear and after several decades there likely is. Normally I'd suggest using a Daily DeOxit product. But in this case I'd say simply replace it with a new pot'.

The difference between 1uF and 100pF is...x10000...ie 4 decades so something is 'out' there. Not going to do the maths now but 100pF would be typical in that position - op amp stability and hf bandwidth limiting. Are you certain about the Silk Screen reference to component matching - it can sometimes get congested due to physical spacing. imo 'NP' does likely indicate non-polarised. Look at CPC if you want to replace as is. But tbh a 50V rated cap will be okay with any reverse voltage it is likely to see in this application - a few volts ?

Anyone know the input Impedance on this unit. The Studiospares 'Spec' is minimal...

Or just wire the DC power connector as centre positive... Seriously - the rest of the electronics world would put the +ve voltage on the centre connector and have the outer connector as -ve and possibly 'screen' so it's reasonable to wonder who's the 'maverick' :-) Yeah - I know it's to do with the power source (battery / DC) switching but it's not that difficult to deal with.

I don't know the '3dB' frequencies but bear in mind that the EQ/Filter slopes and 'Q' values are important in determining how it actually sounds.

It's mainly used to cut out a specific feedback frequency - typically on electroacoustic / acoustic (via mic) guitar but can be useful on other sources.

Not really surprising. Even if noise doesn't get through via normal transformer operation because the frequency is too high then it can transfer via interwinding capacitances.

Alternatively - pump some sort of 'No More Nails' type filler into the space to fill it completely. Leave it for , say, two weeks - don't follow the 24 / 48 hour or whatever hour guidance on the pack. Really need to let all the water / solvent get out of it - should be hard as the wood by then. Then cut away any excess with a craft knife. It'll then take screws and let them cut new threads (suggest to drill pilot hole before screwing).

wrt the original jack. I' d try cleaning the contacts with Caig DeOxit and then IPA (Isopropyl Alcohol not India Pale Ale 😊. And pushing bending the contacts in a bit. Over time they can lose their tension and not make secure contact with the plug.

Assuming you're not touching a piece of earthed equipment / water pipe at the same time then - If the noise goes away when you touch the bridge then it implies that the bridge IS connected to earth (via the amp or whatever is on the end of the bass lead). You are 'earthing' yourself through the bass. You are not earthing the bass because you are not connected to earth yourself. Anyway it's easy enough to test if you have a multimeter with a continuity 'beep' function.

If it's creased but there's no break or tear in the cone then I'd say the acoustic effect will be minimal and recommend leaving as is.

+1 There's a lot of prejudice about Behringer kit. Much of that is their fault of course but I wouldn't dismiss the speakers out of hand. Of course it's quite possible that they'll sound good but not be durable if given a hard time - due to materials, adhesives etc. I did once use one of their head + cab setups - 6 or 8 x10" IIRC as it was in the rehearsal room we were using. No issues.

That seems the best way forward to me if you don't like the metal grill look. I guess cloth also offers a bit more protection against drink spills etc. If you don't have the grill or something else there then it seems a large area over which you'd need to keep the cloth taut. I noticed that the top left speaker is different to the others - larger dustcap ?

Just a thought ... You've tried it withh different leads to make sure it's the socket that is the problem ?

FWIW if I saw '7812' on a TO220 package I'd assume it was a +12V regulator too 😃

Probably about right. The technical innovation comes more from TC / Zoom / Roland etc etc who have the resources to exploit DSP etc. That's very different to a 'boutique' fuzz box - say some variation of a 'fuzz face' circuit - that has an enormous price tag given the component cost. Essentially comes down to economies of scale and manufacture / distribution - if I'm making pedals as my only work and I'm shifting just ten pedals a week I still need to price to make a living - and my unit cost to make will probably be more than the retail cost of a 'cheap' pedal made in China or wherever. And, of course, seeking out / selecting / sorting any 'magic' transistors etc. I can try and bridge the gap by being extra helpful / available etc but the price gap remains huge.

There are 12V and 9V regulators. 12V in does then seem 'wrong' given that there's always some drop across a regulator . But if the drop is low enough and your nominal 12V in is a bit higher than 12V then it might squeeze through depending on how 'low drop' the regulator is. Alternatively if the 12V is clean enough then it will likely just pass through with just a bit of loss. 12V will be fine for the 9V regulator.

It seems you want to put 3 x Mics into one input. So that's not really a 'Splitter' application. That would be more taking a signal from one mic and splitting it to feed more than one input eg a recorder and a mixer. The ART Promix gives you what you need - I'd say the individual level controls are a necessity. It's not a cheap option for you though. If I were spending in that range I'd probably look at spending a bit more on a 'real' mixer - Soundcraft Notepad series etc - that would give you more connectivity options plus individual mic EQ. But maybe you require a physically smaller solution ? You can sometimes pick up discontinued Notepads etc on ebay for £30 or so. But make sure they have the PSU if you're not equipped to get one together yourself. They are +/- 17Vac - technically simple but not easy to get and everyone hates the connector !

What are the chances 😊 So there are actually four gangs there - 2x20K and 2x100K. I guess that you can just use one of each as long as it fits mechanically.

Yes - as it says : "different standards uses the same letters which can be confusing" so you need to consult the datasheet or manufacturer / distributor.

Interesting - although it comes to 48 Euro for a pot inc shipping (I'm assuming OP is in UK). I see they offer three tapers - although need to check what they are as letters to denote can be inconsistent. I guess for tone it's linear but you never know. There's no 20K option but there is 25K - maybe that's close enough for the OP ? Also - it doesn't mention the track composition - so I guess Carbon. It might be worth contactin OMEG in the UK to see if any response ?

+1. I doubt whether 20K / 100K is a readily available combination. I reckon the only realistic way to get what you want on a one off (or even small / moderate basis) without spending "mortgage money" is to build it from existing potentiometer component parts.

Unless you're keeping it as an historic artifact then I say rewire it.

Well there's a lot to remember / forget 😊 Anyway, we can probably agree that it's not a great circuit idea when you lose volume with tone. Personally I don't really use passive tone control much at all.

Me too + the rest. Still am. Cheers.